FIG. 1 illustrates a general constitution of solid state image pick-up devices which utilize the photo-electric converting function, the signal charge accumulating function, and the signal charge transmitting function of a CCD (charge coupled device). This is an example of an interline type CCD image pick-up device which is manufactured through semiconductor integrating technology and comprises: a plurality of photo-electric converting devices 11 for converting the incoming light rays to signal charges; a plurality of vertical transferring sections 12 for transferring the signal charges in the vertical direction; a transmitting gate 14 for transmitting the signal charges generated from the photo-electric converting devices 11 to the vertical transferring sections 12; and horizontal transferring sections 13 for outputting output signals by transferring in the horizontal direction the signal charges transmitted from the vertical transferring sections 12.
Here, the transmission of the signal charges is carried out by utilizing the fact that the CCD device forms low potential wells in the places where the voltage is applied. Thus the vertical transferring section 12 is provided with a plurality of vertical transferring electrodes 15, and the horizontal transferring section 13 is provided with a plurality of horizontal transferring electrodes 16, while vertical and horizontal driving signals .phi.V.sub.1 -.phi.V.sub.3, .phi.H.sub.1 -.phi.H.sub.3 with variable heights are supplied to them, so as for them to transmit the signal charges.
As the method of regenerating the images through a solid state image pick-up device, the usual scanning method is used, which is constituted such that horizontal transferring section 13 repeatedly outputs signals at a predetermined time intervals in such a manner that the picture elements belonging to the same row of the plural vertical transferring sections 12 are outputted by one row at a time, thereby forming the total image.
Thus, a driving pulse generating circuit is provided for controlling the vertical transferring sections 12 and the horizontal transferring sections 13 in order to transmit the signal charges and to output images in certain periods of intervals.
The light rays entering into such a solid state image pick-up device are converted into signal charges by the photo-electric converting device 11, and the converted signal charges are accommodated into potential wells W which are formed also by the photo-electric converting device 11. However, as shown in FIG. 2, if some strong light rays are inputted, and consequently, if the converted signal charges are beyond the charge accommodating capacity of the potential well W, then the excess charges C flow to potential well W' of the vertical transferring section or a nearby photo-electric converting device. Accordingly, in spite of the fact that no actual light rays from an actual object are inputted, the fallacious signals produce the socalled blooming phenomenon which is indicative of white stripes appearing around high luminance images.
Such a blooming phenomenon severely aggravates the picture quality and forms a definite defect in a solid state image pick-up device. In order to overcome this problem, many technical attempts such as the installation of an overflow drain have been made, but so far, no thorough solution has been produced. Accordingly, this blooming phenomenon has an important care-demanding item in designing a solid state image pick-up device.
The conventional measuring method for the blooming phenomenon is constituted such that a spot beam having a height equivalent to 1/10 of the height of the light receiving section of the solid state image pick-up device is irradiated, and the signal charges obtained therefrom are converted to image signals through a signal processing circuit, so that the pictures displayed through an image monitor or wave form monitor are visually observed as to the wave forms or the image quality, thereby recognizing the blooming characteristics.
However, in such a conventional blooming measuring method, during the conversion of the signal charges outputted from the solid state image pick-up device to image signals through a signal processing circuit, the signals are affected by the components of the signal processing circuit and other surrounding conditions, to such a degree that the characteristics of the signals are altered, thereby making it impossible to exactly and precisely measure the blooming characteristics, and also making it impossible to carry out a quantitative analysis.